1. Field of the Invention
This invention relates to a termination system for telecommunication devices, and is particularly concerned with modular interchange termination apparatus for multi-function telecommunication devices, such as key telephones.
2. Description of the Prior Art
Telephone termination systems, particularly those associated with key telephones in a business office environment, have heretofore required a great deal of time and expense in connection with installation, maintenance, and line and function flexibility in providing changes in an alteration of service.
Francis J. Mullin and Raymond B. Ramsey, in their U.S. Pat. No. 3,573,373 disclose a cable terminating system for key telephone closets in which a number of connector blocks, such as the Western Electric 66A or 66B terminal blocks, are mounted within expandable groups on boards which are equipped with prepositioned mounting brackets for the blocks. The brackets stand off from the boards to provide cable runs and jumper wires are extended vertically or horizontally between the brackets with the aid of wire guides. The utilization of such permanent or semi-permanent connections, including lugs and insulation piercing terminals, such as provided by the aforementioned Western Electric terminal blocks, gives rise to problems concerning wiring flexibility. For example, if four incoming lines are available and a key telephone has access to two of the four lines, and access is to be altered to three available lines, additional connections must be individually provided and physically performed at the terminal blocks. From an installation standpoint, this problem is compounded if one of the original two lines is not to service the key telephone, which means that the function conductors associated with the line (ringing, lamps, etc) must be disconnected. Personnel changes in a customer's facility, and changes in customers, causes maintenance of such a connection system to become a problem. Also, when a customer acquires additional floor space, or shifts personnel to different areas of a given floor space, the function conductors associated with each key telephone must be disconnected and/or connected to different terminals of the terminal blocks. In addition to interfering with the customer's business activities, reconfiguration of the connection system requires additional installation time.
Marion L. Humphrey and Ernst A. Tugaudis, in their U.S. Pat. No. 3,869,582 disclose an intrabuilding telephone system in which connections are extended between incoming lines and individual telephones with junction arrays and distribution panels constructed, for example, with standard Amphenol CCB Panels which are described, for example, in "The Denver Plan--CCB A Method of Reducing Central Office Bulge", published by Amphenol Industrial Division of Bunker Ramo Corporation, the assignee of the present invention. In the Humphrey and Tugaudis system, interpanel connections are provided with flexible interconnection possibilities in utilizing well-known patch cord jumpers. At the distant ends of the individual telephone lines, conventional telephone jacks are provided to plug telephones into and out of service.
In his application for U.S. patent, Ser. No. 736,030, filed Oct. 27, 1976, a continuation of Ser. No. 480,852, filed June 19, 1974 (now abandoned) Arie Verhagan discloses an interchange termination system which is constructed on a modular bais and which overcomes the disadvantages associated with systems of the type set forth above. In the Verhagan system, advantages are provided in addition to flexibility in changes of service and relocation of telephones, not heretofore found in the art. As explained by Verhagan, in such termination systems, incoming trunks are extended, usually underground, from a central office to a distribution frame usually located in a basement or other utility area of an office building. The incoming lines are then fed to second terminal blocks located in individual floor riser closets for connection to equipment also located in each closet which operates in conjunction with the key telephones to selectively provide multi-line connections and the associated functions of holding, ringing, lamp lighting and the like which are usually provided with key telephone service.
From an initial installation standpoint, the Verhagan system is less expensive than systems heretofore employed. For example, the terminal blocks and switching and signaling equipment are located in the floor riser closets and the individual key telephones are, of course, located at various positions throughout the building. It is therefore necessary to run a multiplicity of conductors for each line connectible to each key telephone to accommodate the associated functions for holding, ringing, lamp lighting and the like. These conductors are known in the art as "raw" cable. The raw cable is usually a 25 pair, solid conductor, color coded, insulated cable and the extension of such cable between the terminal blocks in the riser closets and the key telephones throughout a building becomes quite expensive in that the same is usually permanently installed in the first instance and left unconnected within the walls when reconfiguration of the system will not permit the use of the same cables because the same are either too short to extend to a new position, or cannot be removed and reused.
According to Verhagan, a modular interchange termination system includes a terminal block for receiving the incoming lines to an office building from a telephone central office. This terminal block is located in a utility closet in the basement or other utility area of the building. The individual lines, often called house lines or house local, are then extended upwardly through the risers of the building which may advantageously be located adjacent an elevator shaft or the like for distribution to the individual floors of the office building. A riser closet is usually located on each floor adjacent to or within the risers. A modular interchange termination system is located in each of these closets and serves the key telephones which are located about the respective floor of the building. The raw cable is extended from the modular interchange termination system to specific locations for connection to the individual telephone instruments. Again, the raw cable is a permanent type wiring and usually extends through conduits in the floor, walls and/or ceiling. The raw cable is connected to the termination system by means of separable connectors having the necessary number of individual matable contacts. The distal ends of these cables are also provided with separable connectors by which individual telephones may be connected, via the cables, to the modular interchange termination system.
The modular interchange termination system includes modules which are similar to the aforementioned CCB panels, and which have a plurality of programmable contacts which may be selectively interconnected by means of plug-in jumper connections, often called patchcords. The contacts of each module are arranged in horizontal and vertical rows which bear similar indicia in the form of color coding to aid in the identification of individual lines which bear corresponding color coding for ease in installation and maintenance.
Three types of modules, all similar in construction, are provided by Verhagan in his modular system. Each of the modules comprises a front panel which carries a plurality of contacts arranged in an array or matrix of rows which extend perpendicular to each other. For convenience, these rows may be thought of as horizontal rows and vertical rows. On the front side of the first panel the contacts, and their surrounding installation, constitute receptacle-type connections for receiving cooperable mating plug-type connections of patch cord connectors. On the rear side of the first panel, the contacts are adapted for a wrapped wire connection, an insulation-pierce connection, or the like. A back panel is connected to the front panel by means of a plurality of stand-off posts. The back panel mounts a plurality of mating connector units each having a plurality of contacts. The contacts of the connector units are interconnected by individual wires, printed circuit conductors or the like to the contacts mounted on the front panel. Each of the mating connector units mounted on the rear panel is connectable to a complementary mating connector unit.
One of the modules is known as the "green field" and is associated with the incoming lines which enter, from the first terminal block, by way of the mating connectors mounted on the rear panel. Advantageously, the green field is thought of as being oriented vertically with adjacent vertical pairs of contacts identifying an incoming line.
The green field is connected to one of more second modules called the "red field."
Each red field receives the incoming lines from the green field, via path cords, and extends the incoming lines to the switching and signaling equipment and key telephone function lines from the signaling and switching equipment back to the red field by way of at least one cable connected by way of a mating connector mounted on the back panel. The red field is generally thought of as being oriented horizontally in groups of rows with the first two rows of each group identifying the incoming telephone line and the remaining rows of a group identifying an extension of that line toward a key telephone along with the switching and signaling functions of that key telephone. The red field is connected by way of patch cords to a "blue field."
The blue field has each vertical row of contacts connected to a separate key telephone by way of the connector mounted on the rear panel, the raw cable for the telephone, and a separable electrical connector at the distal end of the raw cable. Inasmuch as each key telephone is assigned a vertical row of the blue field, and as the red field extends lines in a horizontal arrangement to the blue field, each vertical row of the blue field may provide connections for a plurality of outside lines to each key telephone, and this service may altered, at will, by means of the patch cords. In addition, inasmuch as each key telephone is connected to the blue field by way of a raw cable and a pair of electrical connectors at each end of the cable, a relocation of telephones and telephone service may be readily accomplished by disconnecting and connecting the distal end connectors and/or by interchanging the connectors at the rear panel of the blue field. The system therefore exhibits complete flexibility in service and maintenance.
As mentioned above, each of the telephone lines is color coded and the insulators surrounding each of the panel-mounted contacts is similarly color coded so that service personnel are immediately advised as to line identification. Also, the provision of the electrical connectors mounted on the rear panels provides ease of access for line and equipment testing purposes.
One may refer to U.S. Pat. No. 3,970,802 granted July 20, 1976, to John Peter Nijman and assigned to Bunker Ramo Corporation, which illustrates the modules disclosed by Verhagan and adapted for printed circuit connections between the front panel-mounted contacts and the rear panel-mounted electrical connector units.